I just bought 20+ years old H18 with wings, but they are not attached to the hull. I ordered the attachment kit from Hobie Cat, but the instructions are not very user friendly. Does anyone have a similar boat who would willing to send me pictures of the way the wings attach to the hull.

The basic concept is that the wings hinge on a threaded bolt just inboard of the hull. That bolt (stud) is threaded into a slug inside the trampoline track. The outboard connection is a bent stainless tab located under the outboard bolt head and sticking up outboard of the wing leg strut. A clevis pin passes through the strut and tab and is secured with a key ring.

There would be 4 studs, one at each corner. Out against the hulls. There are 4 tabs on each of the four outboard bolts.

Likely any current instructions refer to the SX wings which may be different from a set that is nearly 20 years old. The attachments described above would be the same for all types. The SX wings are a longer seat and also have a strut angled aft from the rear leg to the deck.

Thank you for the reply. It makes more sense to me now.
I also read the article about the serial number for the Hobie Cats. My question is:
How do you know the year, since there is only one digit? If the digit is 7, it can be 1977, 1987 or 1997. In my boat, the serial number is CCMH2845M864 (?), which does not make much sense, unless the model is 1964. But what is the year: 1968, 78, 88 or 98?

CCMH2845M864 ? Are you reading that off the boat or on a registration record? Perhaps a few digits are mixed up? (It is always possible that the factory mixed it up. They commonly are inscribing the last few numbers while the boat is upside down and already in a box... through a small hole cut in the box)

I'd say there is something wrong with that one...

First, The 18 was first introduced around 1978.

CCMH? I would suspect that this boat was built during peak production on that model. Likely early/mid 1980's. CCMC is the standard Hobie 18 letter (C). Other letters were used when production reached quantities larger than 9,999 boats in one year.

Boats that were 80-81 and around those dates had a year followed by a letter i.e. CCMC2234B80A or something like that. That is before the latest format was used.

I am sure that we followed the current serial number program by 1984.

I suspect that this is likely meant to read CCMH2845M486

Does the boat have the "Red" glue seam? That was a pigment added to the bonding glue for 1984 and later built boats.

Actually, after some cleaning and sanding, it looks like CCMH2845M80H: the 64 is more like 0H (number zero and letter H) or OH (letter O and letter H). Still does not help us much... may it was altered after some body work. I didnt notice any red glue.
Also, after a whole day of work installing the supports for the wings (it took me 4 rivet tools to install these pesky steel rivets), it turns out that the wings are about 2 1/2" shorter than the distance between the front and rear cross bars... It looks like these wings are not made for this boat... oh well, living an learning...
Again, if you can find out what year these boat is that would be good, but dont spend much time on it... it ain't worth the time...

Try the wings on the other side of the boat. I had the same problem you are having but was advised that I was trying to put them on the wrong side. The wing support is cupped and looks like it will wrap around the front crossbar, it dosen't. The cup goes on the far side of the front cross bar and is there to accept the nut.

Thanks for the reply, and I see what you're suggesting about the wings, because they need to be able to turn up and down for trailing. However, they still don't fit: the distance between the two loops is about 2 1/2" shorter than the distance between the base of the two screws I installed on the crossbars... But thank you anyway...